This invention relates to a device for measuring acceleration of a vehicle which is particularly adaptable for use in spacecraft. Accelerometers heretofore known in the art have substantially all been of the mechanical "inertia" type. It is well known that such accelerometers are all incapable of exact accuracy. More specifically, this invention relates to an accelerometer that can measure acceleration by means within the vehicle itself through audio, radio or laser or (light) frequency signals.